Magnetic-Field Confinement Regularisation for Biomedical Electromagnetic Systems

Precise spatial control of magnetic fields in heterogeneous, lossy media remains a central challenge in biomedical technologies such as magnetic resonance imaging (MRI), electromagnetic stimulation, and sensor–prosthetic interfaces. This work presents a computational resonance-confinement framework that adapts principles from magnetic filtering in low-temperature plasmas to improve field localisation and coupling efficiency. A phenomenological harmonic confinement term is introduced into the magnetoquasistatic diffusion equation, acting as a tunable regularisation that biases solutions toward spatially bounded, low-leakage field distributions. The approach is implemented within finite-element models for representative MRI-like and multilayer conductive interface configurations. A normalised resonance-overlap metric quantifies alignment between designed and realised magnetic-energy distributions. Across the evaluated parameter range, confinement-regularised configurations reduced axial field variance by approximately 27% and improved coupling efficiency by up to 31% relative to baseline cases, while maintaining high resonance overlap. These gains were achieved without additional power input or active feedback. The results demonstrate that plasma-inspired topological regularisation offers a computationally tractable strategy for passive field shaping in biomedical electromagnetic systems. The framework is positioned as a simulation-based design methodology. Experimental validation using physical phantoms remains the critical next step.